Number 1 what is it in? A tuna boat or a firebird(weight of car)? I ran a 400 in a 1980 bird and it had a comp cam High Energy 268 that ran the same way. I agree with the guys above.TO HIGH OF GEAR IN THE REAR.That is what is killing you the most.You need headers to breathe.Now what will help you the most (other the 373 posi in the rear)Is a B&M 2000+ hole shot converter.Get those RPM's Up.You can spin a 400 (unbalance)up to about 6100-6200 between shifts.
